The present invention relates to a double-drum winder for the winding of webs on winding cores. It particularly relates to roll cutting machines of the type in which a paper web is fed between two supporting drums for winding on a core which is located above the drums. The roll, as it forms, rests on the drums. Such machines typically have a device for lifting a fully wound roll from the first drum (the web being wrapped at least part way around one of the drums, herein referred to as the first drum), means for cutting the web, a device for holding the newly cut end of the web on the first drum and a device for inserting a new winding core.
Individual smaller rolls of a web are formed from large stock rolls by means of such drum winders. In cooperation with roll-cutting machines, the web withdrawn from a stock roll is cut in the longitudinal direction into individual narrower webs, which are wound by a winding device onto a plurality of winding cores which are located axially alongside of each other. When the wound roll in question has reached the desired diameter, it is removed from the winding device, the web which is still attached to the stock roll is cut, and the new web-end thus formed is attached to the newly inserted winding core.
For carrying out these various steps, there are known methods and apparatus by means of which the replacement of one winding core with another can be effected substantially automatically.
For example, German Offenlengungsschrift No. 27 09 684 discloses a method and a corresponding apparatus in which the completely wound roll is moved from a position in which it rests on both support drums to a second position on top of the first drum, about which the web is partially wrapped. The new winding core is then introduced through the gap produced thereby between the other supporting drum and the complete roll, and the web is fastened to the new winding core. At the same time, the web is cut between the new winding core and the complete roll. With this known apparatus, the finished roll must first of all be moved onto the wrapped support drum, i.e. in a direction opposite the direction in which it must later be conveyed. Only then, after the new winding core has been inserted, is the full roll again lowered and passed over the second support drum, which does not carry the web, onto a lowering table. The time required by the two movements in opposite directions of the complete roll is relatively large.